Developing new strategy to efficiently improve the photocatalytic activity of graphitic carbon nitride (g-CC3N4) for hydrogen evolution is critical for its application in solar energy utilization. In this work, an innovative selective cation replacement process is developed to synthesize copper doped g-C3N4 nanotubes driven by the ion-dipole interaction of metal ions in g-C3N4. The tri-s-triazine units may act as stable frameworks in the sequential cation exchange reaction process, which subsequently leads to the formation of Cu doped g-C3N4 with high specific surface area and nanotube structures. The obtained g-C3N4 exhibits greatly enhanced visible-lightdriven hydrogen evolution of 3.02 mmol h(-1) g(-1), which is about 13 times higher than that of pristine one. Detailed characterization reveals the underlying mechanism of the improved photocatalytic performance on the newly developed g-C3N4, which can provide valuable guides to rationally design new efficient photocatalysts.